Various types of theft-resistant fasteners are known from the patent literature and in the marketplace. In fact, since my present system has first become known, there have been those who suddenly saw theft resistance in fasteners which not even their designers had imagined. A case in point is the over hundred-twenty-year old U.S. Pat. No. 66,585, by H. A. Harvey, which issued July 9, 1867 for Improvement In Screws.
In particular, as H. A. Harvey pointed out in that patent, his object was to construct the head of an gimlet-pointed wood screw of a globular or spherical form, and to provide for driving it without cutting the ordinary nick across its face. As further defined in that Patent No. 66,585, the invention disclosed therein consisted in boring holes obliquely into the head, the direction of which shall be at about an angle of forty-five degrees with the shank of the screw, whereby, with a properly constructed screwdriver, the screw may be driven without injury to the head. As confirmed in the further course of that patent, the objective was to make the globular-headed type of screw competitive with the ordinary flat-headed screw, in terms of appearance and durability. In an effort that the screw thus formed may be held, supported, and driven with the greatest facility in all situations, H. A. Harvey also proposed a special screwdriver including jaws in the form of springs in a slide, bearing pins for entering the oblique holes in the screw head.
In similarity to Harvey, O. A. Smith, as apparent from U.S. Pat. No. 1,330,098, issued Feb. 10, 1920, provided lateral recesses in his screw head and a screwdriver having a pair of projections for entering such recesses in driving engagement.
As an aside, British Patent Specification 388,263, by B. Biasi, dated Feb. 23, 1933, proposed an improved coach screw for railroads with a detachable head which, upon removal, left a bare or threaded screw extension.
Of course, there also arose thereafter the familiar Phillips screw head with a crossed pair of partially cut slots, and the corresponding Phillips screwdriver with its point of crossed ridges.
A variant thereof is apparent from U.S. Pat. No. 2,180,633, by C. G. Holt, issued Nov. 21, 1939, for a screw head having four slots arranged in the configuration of the arms of a cross, and for a screw driver having four corresponding downward projections.
A safety against unauthorized removal of screws, nuts and the like has been proposed by N. Kreuz in his German Patent No. 881,129, published May 13, 1953, and in his French Patent No. 1.038.363, published Sept. 28, 1953. The disclosures of those two patents go to great length in devising various designs and configuration in an effort to thwart any conceivable attempt by unauthorized persons to loosen the fastener. Even an irregular pattern of holes is proposed for receiving a corresponding irregular pattern of pins of a driver that would only be possessed by authorized personnel. However, despite all these efforts, it would appear that a standard tool, such as a good pair of nose pliers, would do for loosening those fasteners, since all that would be necessary is an insertion of as little as one pair of pins or tips into a single pair of opposite holes, and a rotation of such inserted pins or tips about the axis of the fastener, for a loosening of such fastener.
U.S. Pat. No. 2,770,998, by R. F. Schwartz, issued Nov. 20, 1956, discloses a tamper-proof screw having a frusto-conical head with flat tool engaging facets thereon. Again, an approach completely different from Harvey.
The same applies to the disclosure of U.S. Pat. No. 3,134,291, by J. K. Barry, issued May 26, 1964, for Non-Removable Screw. As that title implies, the disadvantage of that approach is that there is no authorized tool for removing the screw according to that patent disclosure. Rather, even an authorized person would have to use the same crude approach as a burglar in order to remove any screw according to that patent.
The same applies to the disclosures of U.S. Pat. Nos. 3,134,292 and 3,302,672, by M. Walton, issued May 26, 1964 and Feb. 7, 1967, respectively, for an irretrievable screw, also known as "one-way screw" and for a screwdriving tool therefor. While such screws are used in great numbers, their problem is, of course, that they have to be destroyed for access to the fastened object, even by authorized personnel.
U.S. Pat. No. 3,411,396, by W. M. Herpich, issued Nov. 19, 1968, for a screw head with inclined driving recesses, for enabling greater driving or tightening torque than removal torque. However, since that patent does not disclose a special tool for removing the screw, it is believed that a screw with that disclosed screw head could still be removed with an ordinary bladed screwdriver.
Somewhat better in this respect is the bolt or nut head disclosed in U.S. Pat. 3,482,481, by S. Newell et al, issued Dec. 9, 1969, since it has an inclined outer surface that resists the application of regular fork or crescent wrenches. However, that bolt or nut head is provided with so many grooves and ridges at the outside thereof, that it still could be gripped and rotated by a pipe wrench of a hardness greater than that of the bolt or nut head, even if the grooves and ridges are included as disclosed in that patent.
The disclosure of British Patent Specification 1 250 110, by H. Hart, published Oct. 20, 1971, expands upon the Kreuz concept set forth above, but it again appears that all that is necessary to undo the fastener is engagement thereof at the two diametrically opposite holes 9 in the diametrical plane A. It would thus appear that the conical fastener could be loosened with simple nose pliers or with another implement having two projecting tips or pins of the type of the two diametrically opposed pins 8 shown in that British patent specification.
It may be for that reason that the subsequent U.S. Pat. No. 3,874,258, by Y. J. Semola et al, issued Apr. 1, 1975, provides the fastener with arcuate lobes in coded configurations, in order to prevent the theft of automobile wheels and tires.
U.S. Pat. No. 4,027,572, by W. G. Burge, issued June 7, 1977, provides for a loosely fitting, inner flanged sleeve in order to prevent removal of its theft-prevention nut by the use of an ordinary pipe wrench. However, that apparently did not solve the problem either, as apparent from the first paragraph of the subsequent U.S. Pat. No. 4,170,918, issued Oct. 16, 1979, also to W. G. Burge. Thus, British Patent Specification No. 1 481 442, by Amerace Corporation, published July 27, 1977, correctly comments that the majority of special wrenching configurations are susceptible to tampering with common tools, such as vise grip pliers, etc. However, it is not seen why the nut and bolt head configurations disclosed in that patent specification could not also be gripped at their lateral notches by vise grip pliers of sufficient hardness and could thus be tampered with as well.
The locking device for a nut of British Patent Specification No. 1 549 321, by Shur-Lok International S.A., published July 25, 1979 is capable of locking the nut against rotation relative to a threaded shaft or other member. However, that patent specification does not disclose any theft-resistant fastener device, since that locking device can be removed by means of a hub remover or other conventional tool.
As if to confirm the fallacy of the above mentioned Kreuz and Hart approaches, U.S. Pat. No. 4,164,967, by K. K. Breuers, issued Aug. 21, 1979, limits itself to two actuation holes arranged at different sides of the screw axis and engageable by the tips of a nose plier or by the special screwdriver disclosed therein.
U.S. Pat. No. 4,356,839, by A. Voynovich, issued Nov. 2, 1982, for tamper resistant valve actuator for fire hydrant, provides such actuator with a bullet-shaped nose having typically three regularly or irregularly spaced shallow indentations or recesses, being preferably teardrop shaped to prevent actuation by a chisel or similar implement. That patent also discloses the manual actuating means in the form of a wrench comprising three threaded studs or set screws that provide cone points for engaging the bullet-shaped actuator for rotation thereof. Hopefully this will work well in the midst of a conflagration, where instantaneous actuation of the fire hydrant for undelayed supply of water is mandatory.
What actually is needed is a nonslip torquing system, as recognized in U.S. Pat. No. 4,466,314, by R. L. Rich, issued Aug. 21, 1984. However, in order to achieve the requisite torquing with essentially axial pins or projections, that system also requires an internal thread in the fastener and an external thread in the torquing tool, which can be a problem in terms of expense, alignment and ease of operation.
U.S. Pat. No. 4,480,514, by L. F. Ponziani, issued Nov. 6, 1984, for Driving Tool for Tamper Resistant Screw, provides the screw head with slots that can easily be engaged by an ordinary chisel or similar tool.
U.S. Pat. No. 4,569,295, by S. R. Rubin et al, issued Feb. 11, 1986, for Automobile Wheel Cover Locking Bolt and Wrench Combination relates how the wrench of prior-art fasteners had a tendency to slip out of alignment with the fastener head, which was very frustrating, especially where the tool had to be used in poor illumination or in busy environments. Accordingly, that patent suggests provision of a coaxial recess in the fastener for receiving a corresponding guide at the bottom of the wrench socket. This, of course, weakens the fastener or at least requires a larger diameter thereof, than without the requisite central recess. The fastener system according to that patent, as well as according to its illustrated prior-art example, also has mating coded key elements and lock impressions for security reasons. It would appear, however, that the illustrated prior-art fastener head and the fastener head newly proposed in that patent could be engaged and rotated by a pipe wrench or similar conventional tool, unless a recess were provided around the fastener as in some of the above mentioned prior-art proposals.
The same appears to apply to the fastener system of French Patent No. 1.496.246, issued Aug. 21, 1967 to Ateliers de Construction de Ruti S.A., disclosing a fastener with undercut wrench engaging notches.
Out of frustration with this prior-art background, the question has been raised, rather surprisingly, whether the unrelated development of ball-and-socket wrenches could have brought relief. For instance, the relatively early British Patent Specification No. 720,486, by Moore & Wright (Sheffield) Limited, inventor Norman Holley, published Dec. 22, 1954, proposes improvements in ratchet-operated mechanical screwdrivers wherein balls around a grooved spindle are selectively engaged and disengaged by lugs of a ball retaining ring. Of course, there would be nothing to prevent the spindle from being rotated by an ordinary pipe wrench or other conventional tool, if that spindle were seen as a fastener removed from the ratchet structure.
The bolt holding tool disclosed in U.S. Pat. No. 3,094,020, by C. J. Wise, issued June 18, 1963, may be used to prevent a bolt from turning while applying or removing a nut thereon. However, the nut disclosed in that patent is still removeable by a conventional fork or crescent wrench.
U.S. Pat. No. 3,354,756, by G. R. Rusk, issued Nov. 28, 1967, discloses a wrench for removing guide pins that have become frozen into core boxes. However, that would make the guide pins simply harder to remove, but not actually theft resistant in the ordinary sense.
U.S. Pat. No. 3,362,267, by W. J. Rozmus, issued Jan. 9, 1968, discloses a roller ratchet wrench that has certain advantages over pawl type wrenches. However, fasteners mentioned or alluded to in that patent are removeable by conventional wrench sockets or other familiar tools.
The same applies to the system of U.S. Pat. No. 3,693,484, by G. H. Sanderson, Jr., issued Sept. 26, 1972, for a snap-on spanner wrench, in which balls are actuated radially inwardly into a continuous annular groove in a cylindrical nipple. In addition to the fact that there is nothing to prevent that nipple to be rotated with a pipe wrench or other conventional tool, it is also a fact that there is nothing in that nipple to prevent the balls from rotating thereabout. To the contrary, an additional pair of axial pins and corresponding axial holes in the corresponding flat end face around the nipple are required to enable the wrench to transmit any rotational power at all.
The ratchet wrenches of U.S. Pat. No. 3,906,822, by Hertelendy et al, issued Sept. 23, 1975, use engaging balls and similar members, to actuate fasteners which, however, can be operated by conventional tools as well, and which are not theft resistant in any sense of the word.
A subsequently disclosed chuck according to British Patent Specification No. 1 557 345, by Kajetan Leitner, published Dec. 5, 1979, cleverly uses the circumferentially distributed balls for gripping the head of a screw or other component during rotative manipulation thereof. However, those balls again are incapable of preventing rotation of the screw or other fastener. Also, there is no theft resistance either, since the screw thus driven can be removed with an ordinary screwdriver.
British Patent Specification No. 1 558 208, by Rubery Owen Conveyancer Limited, published Dec. 19, 1979, prevents inadvertent disconnection of a bayonet type connector. However, as that patent specification discloses in its fourth column, the connection is still releasable with the aid of a small Allen key, and is thus not theft-resistant either.
Somewhat closer to the action appears the internal pipe wrench according to U.S. Pat. No. 3,902,384, by F. O. Ehrler, issued Sept. 2, 1975, since it at least could be argued that the threaded broken-off piece of pipe disclosed therein resists removal from the intact piece of pipe in which it is stuck. In an attempt to remove such piece of pipe, that patent proposes driving circumferentially distributed balls with the aid of a cone radially into the inner wall of that piece of pipe. Of course, since the balls thereby expand the wall of the broken-off piece of pipe into the internally threaded portion of the intact piece of pipe, it is not seen how the desired removal could be easy. Indeed, the disclosure of that patent suggests a type of rocking action in an attempt to loosen "troublesome connections." Besides, there is no way for the balls to drive the externally threaded piece of pipe into the internally threaded bore, and that patented tool would obviously be useless for fastener setting purposes.
The quick-release mechanism for the socket wrench of U.S. Pat. No. 4,187,747, by R. E. Pawlow, issued Feb. 12, 1980, provides a socket-engaging ball and a manually operable actuator therefor, but is not capable of preventing any fastener therein mentioned from being releasable by any conventional wrench.
U.S. Pat. No. 4,198,080, by W. L. Carpenter, issued Apr. 15, 1980, discloses a telescoping-type connector for fluid lines, comprising an inner coupling member having a circumferential groove preceded by circumferentially distributed recesses, and an outer coupling member having circumferentially distributed balls for engaging the inner member at the circumferential groove. According to the disclosure of that patent, every effort is made to prevent the balls from engaging the inner coupling member at the circumferentially distributed grooves. In consequence, that system would appear to be useless for fastener rotation purposes.
U.S. Pat. No. 4,234,277, by Benson et al, was issued Nov. 18, 1980, for Motor Quick-Change Chuck System for Tool Having Cylindrically Shaped Adapter Portion. This is exactly what it says and has nothing to do with theft-resistance fasteners, or any other fasteners for that matter. Accordingly, while that chuck employs typically three balls for engaging corresponding spherically shaped dimples in a cylindrical adaptor portion, such adaptor portion, with its radially outwardly facing dimples, would in no way be protected against rotation and removal by a pipe wrench or similar conventional tool, if such adaptor portion were supposed to be a fastener, or the head of a fastener, by any uncontrolled stretch of the imagination.
By contrast, the stud driving or extracting apparatus according to British Patent Application 2 067 115, by G. Rothenberger, published July 22, 1981, at least could arguably be said to be useful in removing studs that resist extraction. However, while a clever combination of rollers and ramps are provided for that purpose, there obviously is nothing that would prevent a stuck stud to be pulled by a strong pair of pliers or other extracting means.
It can thus be seen that the prior art which has been brought into the picture after my subject invention had been disclosed was as ineffective to bring a solution as the more relevant prior art actually concerned with theft-resistant systems.